Forces of the UN-backed Libyan government said Thursday they progressed against the east-based rival army in the southern part of the capital Tripoli, as the armed conflict continues between the two parties.

"Our brave armed forces have made progress today by controlling new points on the airport road (in southern Tripoli), destroying two tanks and six armed vehicles, and arresting a number of the followers of (General Khalifa) Haftar as their companions fled and left them injured in the battleground," the government forces said in a statement.

The government's airforce has targeted its rival in southern Tripoli and carried out 14 combat sorties in the past three days, the statement said.

The army led by Haftar has been waging a military campaign since early April to take over Tripoli, where the government is based.

According to the World Health Organization, the fighting has killed 653 and injured 3,547 others so far.

Libya has been struggling to undergo a transitional period amid chaos since the fall of former leader Muammar Gaddafi in 2011.